首页 > 代码库 > POJ 2676-Sudoku（DFS）
POJ 2676-Sudoku（DFS）
Sudoku
| Time Limit: 2000MS | Memory Limit: 65536K | |||
| Total Submissions: 14120 | Accepted: 6976 | Special Judge | ||
Description
Sudoku is a very simple task. A square table with 9 rows and 9 columns is divided to 9 smaller squares 3x3 as shown on the Figure. In some of the cells are written decimal digits from 1 to 9. The other cells are empty. The goal is to fill the empty cells with decimal digits from 1 to 9, one digit per cell, in such way that in each row, in each column and in each marked 3x3 subsquare, all the digits from 1 to 9 to appear. Write a program to solve a given Sudoku-task.
Input
The input data will start with the number of the test cases. For each test case, 9 lines follow, corresponding to the rows of the table. On each line a string of exactly 9 decimal digits is given, corresponding to the cells in this line. If a cell is empty it is represented by 0.
Output
For each test case your program should print the solution in the same format as the input data. The empty cells have to be filled according to the rules. If solutions is not unique, then the program may print any one of them.
Sample Input
1 103000509 002109400 000704000 300502006 060000050 700803004 000401000 009205800 804000107
Sample Output
143628579 572139468 986754231 391542786 468917352 725863914 237481695 619275843 854396127
深搜。。
题意：就是传统的数独游戏。。找出一种方案即可。。有spj
对 行，列，以及9个3*3的方块哈希。。然后暴力深搜就行了。。实践证明倒搜比较快
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <string>
#include <cctype>
#include <vector>
#include <cstdio>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#define ll long long
#define maxn 360
#define pp pair<int,int>
#define INF 0x3f3f3f3f
#define max(x,y) ( ((x) > (y)) ? (x) : (y) )
#define min(x,y) ( ((x) > (y)) ? (y) : (x) )
using namespace std;
char ma[11][11];
bool row[11][11],col[11][11],mar[11][11],ok;
int change(int x,int y)
{
if(x>=1&&x<=3) return y%3==0?y/3:y/3+1;
else if(x>=4&&x<=6) return 3+(y%3==0?y/3:y/3+1);
else return 6+(y%3==0?y/3:y/3+1);
}
void dfs(int num)
{
if(ok) return ;
if(num==0)
{
for(int i=1;i<=9;i++)
{
for(int j=1;j<=9;j++)
putchar(ma[i][j]);
puts("");
}
ok=1;
return ;
}
int x=num%9==0?num/9:num/9+1;
int y=num%9==0?9:num%9;
if(ma[x][y]-'0')
dfs(num-1);
else
{
for(int i=1;i<=9;i++)
{
if(!row[x][i]&&!col[y][i]&&!mar[change(x,y)][i])
{
ma[x][y]=i+'0';row[x][i]=1;col[y][i]=1;mar[change(x,y)][i]=1;
dfs(num-1);
ma[x][y]='0';row[x][i]=0;col[y][i]=0;mar[change(x,y)][i]=0;
}
}
}
}
int main()
{
int T;
scanf("%d",&T);
while(T--)
{
memset(row,0,sizeof(row));
memset(col,0,sizeof(col));
memset(mar,0,sizeof(mar));
for(int i=1;i<=9;i++)
scanf("%s",ma[i]+1);
for(int i=1;i<=9;i++)
for(int j=1;j<=9;j++)
if(ma[i][j]-'0')
{
row[i][ma[i][j]-'0']=1;
col[j][ma[i][j]-'0']=1;
mar[change(i,j)][ma[i][j]-'0']=1;
}
ok=0;dfs(81);
}
return 0;
}POJ 2676-Sudoku（DFS）
声明：以上内容来自用户投稿及互联网公开渠道收集整理发布，本网站不拥有所有权，未作人工编辑处理，也不承担相关法律责任，若内容有误或涉及侵权可进行投诉： 投诉/举报 工作人员会在5个工作日内联系你，一经查实，本站将立刻删除涉嫌侵权内容。